Henk is a Dutch citizen living for over 50 years as a foreign resident in Israel. Since 1999 he is serving as a part-time collection manager of the Mollusk and Brachiopod Collections at the Steinhardt Museum.

Henk is especially interested in the taxonomy, systematics and nomenclature of all terrestrial, fluviatile and marine mollusks living in the Middle East and Western Europe. Special subjects of interest are archaeomalacology, distribution of species, Lessepsian migration, terrestrial snails and slugs as pest species and natural enemies of mollusks. Since 1965 Henk has authored more than 2350 publications of which 90% are dealing with mollusks. Currently he is publishing two journals: ‘Triton’ – a biannual journal in English devoted to the study of mollusks and ‘Natural History and Other Notes’ – a quarterly written in English or Dutch dealing with general field work or studies carried out in Israel and the Netherlands.